The transducer structure disclosed herein is adapted for use in the transducer of my co-pending application Ser. No. 843,942 filed Oct. 20, 1977. In that invention, I provided a magnetic assembly within a cylindrical structure, externally threaded. The diaphragm structure was mounted in the base of a tubular member internally threaded to mate with the cylindrical structure and place the magnetic assembly in operative engagement with the diaphragm structure.
The general construction of a transducer such as a conventional bi-polar receiver, called generically a central armature receiver, is shown by U.S. Pat. No. 3,439,130 issued Apr. 15, 1969 to A. J. Chase et al. In that patent, the magnetic subassembly is fabricated on an insulating terminal block which seats within a frame of generally tubular section. Magnetic pole pieces, generally of the shape shown by the patent, may be employed in the present invention.
Customarily in structures such as that of the cited Chase et al patent, the pole pieces are affixed within the terminal block and ground by precision tooling to align the pole tips and space them precisely relative to the block for joinder to the armature and diaphragm assembly.
Air gap adjustment of the concentional type is also shown by U.S. Pat. No. 3,542,974 to Blastic et al as issued Nov. 24, 1970.